Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

What is the Surname of Barbie Doll?

They are three errirs in this question. Can you find them?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

During which month do people sleep the least?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

Can you count the number of triangles inside a triangle?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?